SynopsisThe plasma polymerization of C2F4 was carried out in both continuous wave and pulsed rf discharges to establish the effects of reaction conditions on the kinetics of polymer deposition and the polymer structure. ESCA spectra of the polymer show evidence for -CF3, -CF2, >CF-, and -CHZgroups. Under conditions favoring low deposition rates, the dominant functional group is -CF2-. At higher deposition rates the concentration of -CF2-groups is reduced and a more crosslinked polymer is produced. Both polymer deposition rates and polymer structures were essentially identical when using continuous wave and pulsed rf discharges.

It was found that mesoscale patterned films of titanium dioxide nanocrystals have superior photocatalytic activity as compared to unstructured films. The nanocrystals were adsorbed onto surface-functionalized and crosslinked polymer honeycomb films. After calcination, the porous structure remained and photocatalytic activity was evaluated by the photolytic decomposition of a cyanine dye in aqueous solution.

Ferroptosis is a regulated cell death induced by iron-dependent lipid peroxidation. The heme-responsive transcription factor BTB and CNC homology 1 (BACH1) promotes ferroptosis by repressing the transcription of genes involved in glutathione (GSH) synthesis and intracellular labile iron metabolism, which are key regulatory pathways in ferroptosis. We found that BACH1 re-expression in Bach1−/− immortalized mouse embryonic fibroblasts (iMEFs) can induce ferroptosis upon 2-mercaptoethanol removal, without any ferroptosis inducers. In these iMEFs, GSH synthesis was reduced, and intracellular labile iron levels were increased upon BACH1 re-expression. We used this system to investigate whether the major ferroptosis regulators glutathione peroxidase 4 (Gpx4) and apoptosis-inducing factor mitochondria-associated 2 (Aifm2), the gene for ferroptosis suppressor protein 1, are target genes of BACH1. Neither Gpx4 nor Aifm2 was regulated by BACH1 in the iMEFs. However, we found that BACH1 represses AIFM2 transcription in human pancreatic cancer cells. These results suggest that the ferroptosis regulators targeted by BACH1 may vary across different cell types and animal species. Furthermore, we confirmed that the ferroptosis induced by BACH1 re-expression exhibited a propagating effect. BACH1 re-expression represents a new strategy for inducing ferroptosis after GPX4 or system Xc− suppression, and is expected to contribute to future ferroptosis research.

SYNOPSISApplication of a high continuous electrical field accelerates the orientation kinetics of polar groups at a polymer-water interface and so improves the surface polarity. This is preliminary to adhesion establishment on a polar substrate. Adhesion of PET and gelatin performed under an electric field leads to an increase of the interfacial adhesion properties, due to simultaneous effects of the electric field at the interface. Polar-group orientation at a polymer surface and electrical aspects of adhesion are therefore self-consistent.